The present invention relates to apparatus and method for sensing for unbalanced force produced due to rotation of a cylindrical rotor.
In the present invention a rotor is supported away from a hydrostatic shaft by means of a first flowing gas. The first flowing gas passes through the interior of the hydrostatic shaft, through radial channels in the hydrostatic shaft, and between the rotor and hydrostatic shaft. The first flowing gas causes the rotor to be suspended over the hydrostatic shaft.
The rotor is rotated by means of a second flowing gas that flows over the outer surface of the cylindrical rotor. This second flowing gas causes the rotor to produce an unbalanced force if the cylindrical rotor in not uniform in mass throughout a cylindrical section of the rotor.
The rotating rotor produces a net centrifugal force that is transmitted to a force sensing device, if the overall mass of the rotor is not uniformly balanced. The net centrifugal force is produced due to an unbalanced mass of the rotating rotor. The net centrifugal force produces a force on the separation gas. This unbalanced force is detected by the disclosed unbalanced force sensing apparatus. An unbalanced mass of the rotor is determined from the detected unbalanced force.
A detected unbalanced mass of the rotor is balanced by grinding down one or more portions of the rotor. By alternate sensing and grinding steps, the rotor is very well balanced.
Unbalanced force sensing apparatus for sensing an unbalanced force produced due to rotation of a cylindrical rotor, comprising a shaft having radial gas passageways extending outward from a central longitudinal gas passageway in the shaft, the shaft having end portions, one of the end portions having a gas passageway, first gas supply means connected to the central longitudinal gas passageway of the shaft for suspending the cylindrical rotor over the shaft, second gas supply means for supplying a flowing gas over the cylindrical rotor, the flowing gas for rotating the cylindrical rotor, and force sensing means for sensing an unbalanced force produced due to rotation of the cylindrical rotor around the shaft.